The bill signed Thursday in Sacramento is part of a long-standing campaign by the Karuk Tribe on the Klamath River and environmental groups to restore salmon runs in Northern California.
The new law bans miners from using small gasoline-powered dredges to glean flecks of gold from river bottoms until an environmental review determines how much it harms salmon.
About 3,500 permits are issued each year for suction dredge mining in California, where people come from around the country to experience the rush of finding raw gold.